Vehicle steering assembly

ABSTRACT

A vehicle steering assembly for controlling movement of a vehicle having independently rotatable left and right ground-engaging traction elements. The steering assembly comprises a steering handle coupled to the panel support structure and extending generally upwardly from the panel support structure. The steering handle comprises a laterally-extending crossmember and at least one upright extension member. The crossmember and the upright extension member are rigidly connected to one another so that shifting of the crossmember relative to the extension member is substantially prevented. The steering handle is shiftable in forward and rearward directions to thereby cause corresponding forward and rearward rotation of both of the left and right traction elements. The steering handle is rotatable in clockwise and counterclockwise directions to thereby cause a change in the relative speeds and directions of rotation of the left and right traction elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present non-provisional patent application claims priority to U.S.Provisional Patent Application Ser. No. 62/718,801, filed on Aug. 14,2018, and entitled “VEHICLE STEERING ASSEMBLY,” with the entirety of theabove-identified, previously-filed provisional application being herebyincorporated by reference into the present non-provisional patentapplication.

FIELD OF THE INVENTION

Embodiments of the present invention are generally directed to a vehiclesteering assembly. More particularly, embodiments of the presentinvention are directed to an improved vehicle steering assembly for acompact utility loader.

BACKGROUND OF THE INVENTION

Compact utility loaders are becoming popular options for operators inneed of heavy equipment machines. Compact utility loaders are capable ofoperating a variety of different hydraulically-driven tools orattachments for performing various types of demanding work.Beneficially, however, compact utility loaders are generallymanufactured with a relatively smaller size compared to other heavyequipment machines, which can be beneficial for maneuverability,transport, and storage. Unfortunately, the control systems ofpreviously-used compact utility loaders have been difficult,non-intuitive, and burdensome to use.

Often a compact utility loader will be maneuvered by traction elements(e.g., tracks or wheels) on either side of the loader. Generally, acompact utility loader will include a separate control element (e.g., acontrol handle) for controlling each traction element of the loader. Theneed for an operator to manipulate multiple control elements to maneuvera compact utility loader can make operation of the loader overlydifficult and cumbersome. This is particularly true when the operator isrequired to maintain a free hand to control the loader'shydraulically-driven tools. As such, there is a need for an improvedvehicle steering assembly, which enhances the ability of an operator toefficiently and intuitively control a vehicle, such as compact utilityloader.

SUMMARY OF THE INVENTION

In one embodiment of the present invention, there is provided a vehiclesteering assembly for controlling movement of a vehicle havingindependently rotatable left and right ground-engaging tractionelements. The vehicle comprises a control panel within reach of anoperator of the vehicle. The control panel comprises a panel supportstructure for supporting control mechanisms of the vehicle. The steeringassembly comprises a steering handle coupled to the panel supportstructure and extending generally upwardly from the panel supportstructure The steering handle comprises a laterally-extendingcrossmember and at least one upright extension member. The crossmemberand the upright extension member are rigidly connected to one another sothat shifting of the crossmember relative to the extension member issubstantially prevented. The steering handle is shiftable in forward andrearward directions to thereby cause corresponding forward and rearwardrotation of both of the left and right traction elements. The steeringhandle is rotatable in clockwise and counterclockwise directions tothereby cause a change in the relative speeds and directions of rotationof the left and right traction elements.

In another embodiment of the present invention, there is provided avehicle steering assembly for controlling movement of a vehicle havingindependently rotatable left and right ground-engaging tractionelements. The vehicle comprises a control panel within reach of anoperator of the vehicle. The control panel comprises a panel supportstructure for supporting control or display mechanisms of the vehicle.The steering assembly comprises a plurality of depressible buttonscoupled to the panel support structure and configured to cooperativelycontrol the speed and direction of rotation of the left and righttraction elements. The steering assembly additionally comprises asteering handle coupled to the panel support structure and positionedgenerally over the depressible buttons. The steering handle comprises alaterally-extending crossmember, an upright extension member, and abase. The base presents a lower surface having a curved topography. Thelower surface is configured to depress the buttons in response tomanipulation of the steering handle by the operator of the vehicle.

In another embodiment of the present invention, there is provided amethod for controlling movement of a vehicle having independentlyrotatable left and right ground-engaging traction elements. The methodincludes a step of providing a steering handle comprising alaterally-extending crossmember and an upright extension memberextending away from a control panel of the vehicle. The crossmember andthe upright extension member are rigidly connected to one another sothat shifting of the crossmember relative to the extension member issubstantially prevented. An additional step includes shifting thesteering handle in a forward direction to cause forward rotation of bothof the left and right traction elements. An additional step includesshifting the steering handle in a rearward direction to cause rearwardrotation of both of the left and right traction elements. A further stepincludes rotating the steering handle in a clockwise or counterclockwisedirection to cause to cause the left and right traction elements torotate in opposing directions.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the present invention are described herein with referenceto the following drawing figures, wherein:

FIG. 1 is a left perspective view of a vehicle, in the form of a compactutility loader, with a steering control assembly according toembodiments of the present invention;

FIG. 2 is a top plan view of the compact utility loader of FIG. 1;

FIG. 3 is a top plan view of a control panel from the compact utilityloader of FIGS. 1 and 2;

FIG. 4 is a rear elevation view of the control panel from FIG. 3;

FIG. 5 is an exploded view of a steering control assembly from thecontrol panel from FIGS. 3 and 4;

FIG. 6 is a steering handle and a handle connection member from thesteering control assembly from FIG. 5;

FIG. 7a is a top plan view of the steering control assembly from FIG. 5,particularly showing the steering control assembly in a neutralposition;

FIG. 7b is side elevation view of the steering control assembly fromFIG. 7a , particularly showing a vertical cross section of a steeringhandle, a handle connection member, and a portion of a steeringcontroller;

FIG. 8a is a top plan view of the steering control assembly from FIG. 5,particularly showing the steering control assembly shifted in a forwardposition;

FIG. 8b is side elevation view of the steering control assembly fromFIG. 8a , particularly showing a vertical cross section of a steeringhandle, a handle connection member, and a portion of a steeringcontroller;

FIG. 9a is a top plan view of the steering control assembly from FIG. 5,particularly showing the steering control assembly shifted in a rearwardposition;

FIG. 9b is side elevation view of the steering control assembly fromFIG. 9a , particularly showing a vertical cross section of a steeringhandle, a handle connection member, and a portion of a steeringcontroller;

FIG. 10a is a top plan view of the steering control assembly from FIG.5, particularly showing the steering control assembly rotated in aclockwise position;

FIG. 10b is side elevation view of the steering control assembly fromFIG. 10a , particularly showing a vertical cross section of a steeringhandle, a handle connection member, and a portion of a steeringcontroller;

FIG. 11a is a top plan view of the steering control assembly from FIG.5, particularly showing the steering control assembly rotated in acounterclockwise position;

FIG. 11b is side elevation view of the steering control assembly fromFIG. 11a , particularly showing a vertical cross section of a steeringhandle, a handle connection member, and a portion of a steeringcontroller;

FIG. 12 is a vertical cross section of the steering control assemblyfrom FIG. 5;

FIG. 13a is a top plan view of a handle connection member from thesteering control assembly of FIG. 12;

FIG. 13b is a perspective view of the handle connection member from FIG.13 a;

FIG. 13c is a side elevation view of the handle connection member fromFIGS. 13a and 13 b;

FIG. 13d is an additional side elevation view of the handle connectionmember from FIGS. 13a, 13b , and 13 c.

FIG. 14 is a top plan view of a horizontal cross section of the steeringcontrol assembly from FIG. 12;

FIG. 15 is a perspective view of the horizontal cross section of thesteering control assembly from FIG. 14;

FIG. 16 is a perspective view of a steering control assembly accordingto additional embodiments of the present invention;

FIG. 17 is an exploded view of the steering control assembly from FIG.16, with a portion of a steering handle cut away to show a handleconnection assembly;

FIG. 18 is an exploded view of the handle connection assembly from FIG.17 in conjunction with a handle securement structure from the steeringcontrol assembly;

FIG. 19 is a bottom perspective view of a pedestal from the handleconnection assembly from FIG. 18;

FIG. 20a is a top plan view of a horizontal cross section of thesteering control assembly from FIG. 16;

FIG. 20b is a perspective view of the horizontal cross section of thesteering control assembly from FIG. 20 a;

FIG. 21 is a bottom perspective view of a steering handle and a handleconnection assembly from the steering control assembly from FIG. 16;

FIG. 22 is vertical cross section of the steering control assembly fromFIG. 16;

FIG. 23a is a top plan view of the steering control assembly from FIG.16, particularly showing the steering control assembly in a neutralposition;

FIG. 23b is side elevation view of the steering control assembly fromFIG. 23a , particularly showing a vertical cross section of a steeringhandle, a handle connection assembly, and a portion of a steeringcontroller;

FIG. 24a is a top plan view of the steering control assembly from FIG.16, particularly showing the steering control assembly shifted in aforward position;

FIG. 24b is side elevation view of the steering control assembly fromFIG. 24a , particularly showing a vertical cross section of a steeringhandle, a handle connection assembly, and a portion of a steeringcontroller;

FIG. 25a is a top plan view of the steering control assembly from FIG.26, particularly showing the steering control assembly shifted in arearward position;

FIG. 25b is side elevation view of the steering control assembly fromFIG. 25a , particularly showing a vertical cross section of a steeringhandle, a handle connection assembly, and a portion of a steeringcontroller;

FIG. 26a is a top plan view of the steering control assembly from FIG.16, particularly showing the steering control assembly rotated in aclockwise position;

FIG. 26b is side elevation view of the steering control assembly fromFIG. 26a , particularly showing a vertical cross section of a steeringhandle, a handle connection assembly, and a portion of a steeringcontroller;

FIG. 27a is a top plan view of the steering control assembly from FIG.16, particularly showing the steering control assembly rotated in acounterclockwise position;

FIG. 27b is side elevation view of the steering control assembly fromFIG. 27a , particularly showing a vertical cross section of a steeringhandle, a handle connection assembly, and a portion of a steeringcontroller;

FIG. 28a is a side elevation schematic view of an additional embodimentof a steering control assembly in which a steering handle is configuredto forwardly and rearwardly translated along a rail; and

FIG. 28b is side elevation schematic view of the steering controlassembly from FIG. 28 a.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description of the present invention referencesvarious embodiments. The embodiments are intended to describe aspects ofthe invention in sufficient detail to enable those skilled in the art topractice the invention. Other embodiments can be utilized and changescan be made without departing from the scope of the present invention.The following detailed description is, therefore, not to be taken in alimiting sense. The scope of the present invention is defined only bythe appended claims, along with the full scope of equivalents to whichsuch claims are entitled.

In this description, references to “one embodiment,” “an embodiment,” or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment,” “an embodiment,” or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the present technology can include a variety of combinationsand/or integrations of the embodiments described herein.

Broadly, embodiments of the present invention are directed to a steeringcontrol assembly for a vehicle, such as for a compact utility loader.FIGS. 1 and 2 show a vehicle in the form of a compact utility loader 10(hereinafter “loader 10”) equipped with a steering control assembly12(a) that includes an improved steering handle 14(a). The steeringhandle 14(a) controls movement of the loader 10. Movement of the loader10 is provided by independently rotatable left and right tractionelements 16 (e.g., left and right endless tracks).

As shown in FIGS. 1 and 2, the loader 10 may include an operatorplatform 18 on which the operator stands while operating the loader 10.The loader 10 has a control panel 20 within reach and view of theoperator. The control panel 20 includes a panel support structure 22 towhich the steering control assembly 12(a) is connected. The loader 10also includes a pair of lift arms 24 to which a working attachment 26(e.g., a loader bucket) is connected.

The loader 10 includes a power source (not shown), such as a dieselengine positioned below a hood 28 of the loader 10, for powering theloader's 10 drive system and loader system. In certain embodiments, thepower source can be a turbocharged diesel engine of less than 25horsepower. Preferably, the power source has more than 20 horsepower.The drive system includes the loader's 10 drive train (e.g., hydraulicmotors and/or a hydrostatic transmission) and the left and righttraction elements 16 (e.g., tracks). The loader system includes theloader's 10 lift arms 24 and the working attachment 26 (e.g., loaderbucket).

Although FIGS. 1 and 2 show a compact utility loader 10 with tractionelements 16 in the form of endless tracks, the loader 10 can be any typeof vehicle having independently rotatable left and right tractionelements 16 (e.g., tracks or wheels), such as, for example, a skid steerloader, an excavator, a tractor, or a bulldozer.

Although FIGS. 1 and 2 show the working attachment 26 in the form of aloader bucket connected to the end of the lift arms 24, the workingattachment 26 could be selected from a variety of different usefultools, such as, for example, a trencher, a tiller, a posthole digger, amower, a fork lift, a grapple rake, a hydraulic breaker, a snow thrower,a box rake, a stump grinder, a utility blade, or a trench filler.

Turning to FIG. 3 a top view of the loader's 10 control panel 20 isshown, illustrating that the control panel 20 can include an informationportion, such as gauges, graphic displays, and the like, which providesvisual information to the operator. The control panel 20 canadditionally include a control portion, which can be manuallymanipulated by the operator to control the loader 10. The controlportion of the control panel 20 can include switches, the steeringhandle 14(a), a throttle handle 30, and a loader handle 32.

As illustrated by the arrows in FIG. 3, the steering handle 14(a), thethrottle handle 30, and the loader handle 32 can be manually manipulatedin various directions to control movement and speed of various portionsof the loader 10. In particular, the steering handle 14(a) can bemanually manipulated forwardly and rearwardly and can be manuallytwisted in clockwise and counterclockwise directions to control thespeed and direction of rotation of the left and right traction elements16. As used herein, the terms “forward” or “forwardly” refer to adirection towards a front of the loader 10, such as where the workingattachment 26 is connected to the loader 10. The terms “rearward” or“rearwardly” refer to a direction towards a back of the loader 10, suchas where the operator stands on the operator platform 18 to operate theloader 10. The terms “right” and “left” means a right direction and aleft direction, respectively, when viewing forwardly from the back ofthe loader 10. The terms “clockwise” and “counterclockwise” means aclockwise direction and a counterclockwise direction, respectively, whenlooking down on the applicable component from above the component. Thus,with respect to the view of the control panel 20 on FIG. 2, a forwarddirection is toward the left side of the figure, a rearward direction istoward the right side of the figure, a left direction is toward thebottom side of the figure, a right direction is toward the top side ofthe figure, a clockwise direction is clockwise (as looking down on theloader 10), and a counter-clockwise direction is counter-clockwise (aslooking down on the loader 10).

FIG. 4 is a vertical view from the rear of the panel support structure22 of the control panel 20, with the panel support structure shownsupporting the steering control assembly 12(a), a throttle controlassembly 40, and a lift control assembly 42. The steering, throttle, andlift control assemblies 12(a), 40, and 42 include manually movablehandles (i.e., steering handle 14(a), throttle handle 30, and lifthandle 32, respectively) each being connected to a controller. Thehandles 14(a), 30, 32 extending generally above the panel supportstructure 22 and the corresponding controllers extending generally belowthe panel support structure 22. Each controller is rigidly coupled tothe panel support structure 22 and each handle 14(a), 30, 32 isshiftable relative to the controller to which it is coupled. In someembodiments, the controllers may be secured to the panel supportstructure 22 in a manner that permits an upper portion of thecontrollers (e.g., depressible buttons disclosed in more detail below)to extend upward above the panel support structure 22. Although notshown in the drawing, a protective cover (e.g., flexible boot) can beattached to the shaft of each handle 14(a), 30, 32 to prevent dust anddebris from entering the controllers at the base of the shaft.

FIG. 5 is an exploded view of the steering control assembly 12(a). Asshown in FIG. 5, the controller of the steering control assembly 12(a)is a steering controller 44(a), which in certain embodiments may be ahydraulic pilot control valve in communication with the loader's 10drive train (e.g., hydraulic motors and/or a hydrostatic transmission).The steering controller 44(a) is equipped with four depressible buttons46 that cooperatively control the speed and direction of rotation of theloader's 10 traction elements 16 (e.g., tracks or wheels) viacommunication between the steering controller 44(a) and the loader's 10drive train (e.g., hydraulic motors and/or a hydrostatic transmission).A front left button 46 may control the forward direction of the left thetraction element 16, while a rear left button 46 may control therearward direction of the left the traction element 16. In someembodiments, the rear left button 46 will be position behind the frontleft button 46. Similarly, a front right button 46 may control theforward direction of the right the traction element 16, while a rearright button 46 may control the rearward direction of the right thetraction element 16. In some embodiments, the rear right button 46 maybe position behind the front right button 46. In addition, the frontright and the rear right buttons 46 may be positioned, respectively, tothe right of the front left and the rear left buttons 46. The steeringhandle 14(a) is coupled to the steering controller 44(a) and is used todepress the buttons 46 in a manner that, as will be described in moredetail below, allows for simple and intuitive control of the movement ofthe loader.

Remaining with FIG. 5, the steering control assembly 12(a) includes ahandle securement structure 50(a) that is used to connect the steeringhandle 14(a) to the steering controller 44(a) in a manner that allowsthe steering handle 14(a) to be shifted forward, shifted rearward,rotated clockwise, and rotated counterclockwise relative to the steeringcontroller 44(a), as described in more detail below. In someembodiments, the handle securement structure 50(a) will be rigidlysecured to the steering controller 44(a) via a plurality of threadedfasteners that extend down through both the handle securement structure50(a) and the steering controller 44(a). The steering controller 44(a)may itself be rigidly secured to the panel support structure 22 via aplurality of threaded fasteners that extend down through both the panelsupport structure 22 and the steering controller 44(a).

The steering handle 14(a) may include an upper crossmember 52, a lowerbase 54, and an upright extension member 56 extending between the base54 and the crossmember 52. The crossmember 52 and the upright extensionmember 56 can be connected in a generally T-shaped configuration. Insome embodiments, the crossmember 52 and the upright extension member 56may be rigidly connected to one another so that shifting of thecrossmember 52 relative to the upright extension member 56 issubstantially (or completely) prevented. Furthermore, in someembodiments, the steering control assembly 12(a) will be connected tothe panel support structure 22 in such a manner that the crossmember 52is substantially (or completely) prevented from lateral shiftingrelative to the panel support structure 22. In such embodiments, forinstance, only forward, rearward, and rotating movements of the steeringhandle 14(a) relative to the panel support structure 22 will bepermitted.

A bottom of the base 54 may presents a curved lower or bottom surface 57that is configured to contact the depressible buttons 46 and selectivelydepress the buttons 46 as the steering handle 14(a) is manuallymanipulated. In some of such embodiments, the crossmember 52, theupright extension member 56, and the base 54 will be integrally formedfrom a unitary piece of material.

Although the crossmember 52 of the steering handle 14(a) is depictedherein as being a substantially straight elongated member that isconnected to the top of the upright extension member 56 to form aT-shape configuration, it should be understood that the crossmember 52can take on a variety of shapes for facilitating manual grasping by theoperator of the loader 10. For example, the crossmember 52 can have anirregular ergonomic shape that conforms to the hand of the operator. Incertain specific embodiments, the steering handle 14(a) will onlyinclude a single upright extension member 56.

FIG. 6 shows the bottom of the steering handle 14(a) in more detail. Inparticular, FIG. 6 shows that the curved bottom surface 57 of the base54 includes a curved topography with a substantially flat front section60, a substantially flat rear section 62, a pair of left-side downwardlysloping sections 64, and a pair of right-side downwardly slopingsections 66. The left-side downwardly sloping sections 64 are formed onthe sides of a left downward projection 68 of the base 54. It should beunderstood that the left downward projection 68 extends down below thefront and rear sections 60, 62. The right-side downwardly slopingsections 66 are formed on the sides of a right downward projection 69 ofthe base 54. It should be understood that the right downward projection69 extends down below the front and rear sections 60, 62.

FIG. 6, also shows that the base 54 includes an internal opening withinwhich a handle connection member 70(a) is received. The handleconnection member 70(a) is used to connect the steering handle 14(a)with the steering controller 44(a) in a manner that allows the steeringhandle 14(a) to be shifted forward, shifted rearward, rotated clockwise,and rotated counterclockwise relative to the steering controller 44(a),as described in more detail below.

FIGS. 7a (top view) and 7 b (side view) show the steering controlassembly 12(a) in a neutral position. When the steering control assembly12(a) is in the neutral position, none of the depressible buttons 46 aredepressed enough to cause rotation of the right or left tractionelements 16 of the loader 10. The steering control assembly 12(a) isbiased toward this neutral position so that if the operator of theloader 10 releases a hand grip on the steering handle 14(a), the loader10 stops.

As illustrated by FIG. 7b , the steering controller 44(a) includes, foreach depressible button 46, a variable switch 71 (or pilot valve spool)and a biasing mechanism 72 for biasing the depressible buttons 46upwardly. The variable switch 71 may comprise a position sensor thatmeasures the depth of depression of the depressible button 46 andpermits the speed of rotation of the traction elements 16 to becontrolled in a manner that is proportional to the depth of depressionof the depressible button 46. In some embodiments, as noted above, thesteering controller 44(a) may be a hydraulic pilot control valve andmovement of the depressible buttons 46 directly adjusts the flow orpressure of hydraulic fluid through the control valve. For example, eachof the depressible buttons 46 may activate an associated variable switch71 and/or may move an associated spool in the steering controller 44(a)when the depressible button 46 is depressed. Such actuation of thevariable switch 71 and/or the spool will generate (or change) a pilotpressure signal that is sent from the steering controller 44(a) to theloader's 10 drive train (e.g., the hydrostatic transmission thatcontrols the hydraulic motors). The pilot pressure signal sent to theloader's 10 drive train will be based on the depth at which thedepressible button 46 is depressed. As such, when the depressible button46 is fully depressed, a pilot pressure signal is sent to the loader's10 drive train (e.g., to the hydrostatic transmission) to cause theassociated traction element 16 to be rotated at a maximum rate. If thedepressible button 46 is depressed a lesser amount (i.e., less than afull depression), a pilot pressure signal is sent to the loader's 10drive train (e.g., to the hydrostatic transmission) to cause theassociated traction element 16 to be rotated at a rate that is less thanthe maximum rate. It is further understood that one depressible button46 (e.g., the front left button 46) is used to generate a pilot controlsignal that causes the left traction element 16 to rotate in a forwarddirection, while another depressible button 46 (e.g., the rear leftbutton 46) is used to generate a pilot control signal that causes theleft traction element 16 to rotate in a rearward direction. Similarly,one depressible button 46 (e.g., the front right button 46) is used togenerate a pilot control signal that causes the right traction element16 to rotate in a forward direction, while another depressible button 46(e.g., the rear right button 46) is used to generate a pilot controlsignal that causes the right traction element 16 to rotate in a rearwarddirection.

The biasing mechanism 72 associated with each depressible button 46pushes the button 46 up against the bottom surface 57 of the steeringhandle 14(a). When the steering handle 14(a) is not being manuallymanipulated out of the neutral position, all the depressible buttons arefully extended and the steering handle 14(a) is maintained in theneutral position by the depressible buttons 46 pushing up against thesubstantially flat front and rear sections 60, 62 of the curved bottomsurface 57 of the base 54.

FIGS. 7a and 7b show that the steering handle 14(a) is connected to thesteering controller 44(a) in a manner that allows the steering handle14(a) to be shifted/tilted forward and rearward on a tilt axis 74.Further, the steering handle 14(a) is connected to the steeringcontroller 44(a) in manner that allows the steering handle 14(a) to berotated/twisted clockwise and counterclockwise on a twist axis 76. Thetilt axis 74 and twist axis 76 are maintained substantiallyperpendicular to one another, even during shifting or rotating of thesteering handle 14(a).

As shown in FIGS. 8a (top view) and 8 b (side view) shifting thesteering handle 14(a) forward on the tilt axis 74 (See FIG. 8b ),without rotating the steering handle 14(a) on the twist axis 76 (SeeFIG. 8b ), depresses the front left and right depressible buttons 46.When the front left and right depressible buttons 46 are depressed anequal amount, as shown in FIGS. 8a and 8b , the left and right tractionelements 16 rotate forward at substantially the same speed, so theloader 10 travels straight forward. It should be understood that thefurther the front left and right depressible buttons 46 are depressedthe faster the left and right traction elements 16 will rotate so as toincrease the speed of the loader 10. As such, when the steering handle14(a) is shifted fully forward, the left and right front depressiblebuttons 46 will be depressed a maximum amount, and the left and righttraction elements 16 will rotate forwardly at a maximum rate to causethe loader to drive forward at a maximum speed.

As shown in FIGS. 9a (top view) and 9 b (side view), shifting thesteering handle 14(a) rearward on the tilt axis 74, without rotating thesteering handle 14(a) on the twist axis 76, depresses the rear left andright depressible buttons 46. When the rear left and right depressible46 buttons are depressed an equal amount, as shown in FIGS. 9a and 9b ,the left and right traction elements 16 rotate reward at substantiallythe same speed, so the loader 10 travels straight backward (i.e., inreverse). It should be understood that the further the rear left andright depressible buttons 46 are depressed the faster the left and righttraction elements 16 will rotate so as to increase the speed of theloader 10. As such, when the steering handle 14(a) is shifted fullyrearward, the left and right rear depressible buttons 46 will bedepressed a maximum amount, and the left and right traction elements 16will rotate rearwardly at a maximum rate to cause the loader to drivebackward at a maximum speed.

As shown in FIGS. 10a (top view) and 10 b (side view), rotating thesteering handle 14(a) clockwise on the twist axis 76, without shiftingthe steering handle 14(a) forward or rearward on the tilt axis 74,depresses the front left and rear right depressible buttons 46. When thefront left and rear right depressible buttons 46 are depressed an equalamount and the front right and rear left depressible buttons 46 are notdepressed, as shown in FIGS. 10a and 10b , the left and right tractionelements 16 rotate at substantially the same speed, with the lefttraction element 16 rotating forward and the right traction element 16rotating rearward. In this configuration, the loader 10 turns clockwisewithout traveling forward or backward. It should be understood that thefurther the front left and rear right depressible buttons 46 aredepressed the faster the left and right traction elements 16 will rotateso as to increase the turning speed or severity of the turn (i.e., theright turn) of the loader 10. As such, when the steering handle 14(a) isrotated clockwise a full amount forward, the front left and rear rightdepressible buttons 46 will be depressed a maximum amount, and the leftand right traction elements 16 will rotate oppositely at a maximum rateto cause the loader to turn in a clockwise direction at a maximumspeed/severity.

As shown in FIGS. 11a (top view) and 11 b (side view), rotating thesteering handle 14(a) counterclockwise on the twist axis 76, withoutshifting the steering handle 14(a) forward or rearward on the tilt axis74, depresses the front right and rear left depressible buttons 46. Whenthe front right and rear left depressible buttons 46 are depressed anequal amount and the front left and rear right depressible buttons 46are not depressed, as shown in FIGS. 11a and 11b , the right and lefttraction elements 16 rotate at substantially the same speed, with theright traction element 16 rotating forward and the left traction element16 rotating rearward. In this configuration, the loader 10 turnscounterclockwise without traveling forward or backward. It should beunderstood that the further the front right and rear left depressiblebuttons 46 are depressed the faster the left and right traction elements16 will rotate so as to increase the turning speed or severity of theturn (i.e., the left turn) of the loader 10. As such, when the steeringhandle 14(a) is rotated counterclockwise a full amount forward, the rearleft and front right depressible buttons 46 will be depressed a maximumamount, and the left and right traction elements 16 will rotateoppositely at a maximum rate to cause the loader to turn in acounterclockwise direction at a maximum speed/severity.

When the steering handle 14(a) is simultaneously tilted (forward orrearward) and twisted (clockwise or counterclockwise), both the speed(fast or slow) and direction of travel (forward, backward, and turning)of the loader 10 are simple and intuitively controlled by the operatorusing a single one hand on the steering handle 14(a).

FIG. 12 is a sectional view of the steering handle 14(a) and steeringcontroller 44(a) in the neutral position. FIG. 12 also shows how thesteering handle 14(a) is coupled to the steering controller 44(a) by atilt hinge 84 and a twist hinge 86. The tilt hinge 86 is configured topermit the steering handle 14(a) to rotate relative to the steeringcontroller 44(a) (and the panel support structure 22) on the tilt axis74 (See FIG. 7b ), while the twist hinge 86 is configured to permit thesteering handle 14(a) to rotate relative to the steering controller44(a) (and panel support structure 22) on the twist axis 76 (See FIG. 7b).

The tilt hinge 84 can be formed by the handle securement structure50(a), the handle connection member 70(a), and a hinge pin 88. Morespecifically, the handle securement structure 50(a) is rigidly coupledto the steering controller 44(a), the handle connection member 70(a) isconnected to the steering handle 14(a), and the hinge pin 88 extendsthrough openings in both the handle connection member 70(a) and thehandle securement structure 50(a) to secure the components together in amanner that permits the tilting of the handle connection member 70(a)relative to the handle securement structure 50(a) on the tilt axis 74.Generally, the hinge pin 88 is aligned with the tilt axis 74.

The twist hinge 76 can be formed by the handle connection member 70(a)and the base 54 of the steering handle 14(a). More specifically, thehandle connection member 70(a) includes a head 90 that is received in aninternal cavity of the base 54 in a manner that permits the steeringhandle 14(a) to rotate relative to the head 90 and the handle connectionmember 70(a) on the twist axis 76. Generally, the head 90 and/or thehandle connection member 70(a) are aligned with the twist axis 76.Correspondingly, the upright extension member 56 of the steering handle14(a) will generally be aligned with and/or centered on the twist axis76, while the crossmember 52 is perpendicular to the twist axis 76 withthe twist axis 76 extending through the crossmember 52.

As such, the steering control assembly 12(a) may comprises a handleconnection assembly for attaching the steering handle 14(a) to the panelsupport structure 22, whereby said handle connection assembly comprisesthe tilt hinge 84 and the twist hinge 86. The tilt hinge 84 isconfigured to permit the steering handle 14(a) to tilt forward andrearward relative to the panel support structure 22 on a tilt axis 74,while the twist hinge 86 is configured to permit the steering handle14(a) to twist clockwise and counterclockwise relative to the panelsupport structure 22 on a twist axis 76.

FIGS. 13a-d provides various views of the handle connection member 70(a)that can be received within the internal cavity of the steering handle14(a). Specifically, FIGS. 13a-d show that the handle connection member70(a) can includes an extension member 92, a neck 94, the head 90, and aprojection 96.

The extension member 92 includes an attachment opening 98 through whichthe hinge pin 84 can extend, so as to couple the handle connectionmember 70(a) to the steering controller 44(a) (and the panel supportstructure 22) via the handle securement structure 50(a) in a manner thatpermits pivoting of the handle connection member 70(a) relative to thepanel support structure 50(a) on the tilt axis 74. The head 90 isconfigured to be received in a broad portion of the internal cavity ofthe steering handle 14(a), as illustrated in FIG. 12. The neck 94 isconfigured to be received in a narrow portion of the internal cavity ina manner that prevents the head 90 from being pulled out of the internalcavity but permits rotation of the steering handle 14(a) relative to thehandle connection member 70(a) on the twist axis 76. The projection 96of the handle connection member 70(a) extends upwardly from the head 90and is received in an upper portion of the internal cavity of thesteering handle 14(a).

FIG. 14 is a horizontal cross-sectional view cut through the steeringhandle 14(a) at the very top of the internal cavity that receives thehead 90 of the handle connection member 70(a). FIG. 14 shows that thesteering handle 14(a) includes stops 100 that extend into the broadportion of the internal cavity at the same level as the projection 92 ofthe handle connection member 70(a). These stops 100 may form part of atwist stop assembly, which are configured to be positioned within thesteering handle 14(a) to restrict rotation of the steering handle 14(a)on the twist axis 76 within a certain range. When the steering handle14(a) is fully twisted in a clockwise or counterclockwise manner, stopsurfaces 102 of the projection 92 contact the stops 100 and preventfurther rotation of steering handle 14(a) relative to the handleconnection member 70(a), steering controller 44(a), and panel supportstructure 22.

In some embodiments, the steering handle 14(a) is rotatable on the twistaxis 76 through a twist range of motion that is between 15 and 80degrees, or 25 and 60 degrees, or 30 and 50 degrees. In addition, thesteering handle 14(a) is shiftable on the tilt axis through a tilt rangeof motion that is between 15 and 80 degrees, or 25 and 60 degrees, or 30and 50 degrees.

Stating the above differently, in some embodiments, the handleconnection assembly comprises a panel attachment piece (e.g., the handlesecurement structure 50(a) and/or upper portions of the steeringcontroller 44(a)), a handle attachment piece (e.g., handle connectionmember 70(a)), and a tilt hinge pin 88. The panel attachment piece canbe attached to the panel support structure 22. The handle attachmentpiece can be attached to the handle 14(a). And the steering handle 14(a)and the panel attachment pieces are coupled to one another by the tilthinge pin 88, with the tilt hinge pin 88 extending along the tilt axis74. In some embodiments, the panel attachment piece will be rigidlycoupled to the panel support structure 22, and the handle attachmentpiece will be rotatably coupled to the steering handle 14(a). The handleattachment piece includes a upper broadened head. The steering handle14(a) defines an internal head-receiving cavity within which saidbroadened head is received to thereby couple the handle attachment pieceto the steering handle 14(a). As a result, the steering handle isrotatable relative to the broadened head on the twist axis 76. Finally,the broadened head includes at least one projection, and the steeringhandle 14(a) includes at least one stop member. Contact between theprojection and the stop member restricts rotation of the steering handle14(a) relative to the panel support structure 22 on said twist axis 76.

As shown in FIGS. 14 and 15, as well as FIG. 7b , the steering handle14(a) can be formed of two halves—a first handle half 14(a)(i) and asecond handle half 14(a)(ii). With the steering handle 14(a) in theneutral, upright position, the first handle half 14(a)(i) may berearward of the second handle half 14(a)(ii) and separated by a verticalplane. The first handle half 14(a)(i) may be secured to the secondhandle half 14(a)(ii) via one or more forward/rearward extendingfasteners. In some embodiments, the first handle half 14(a)(i) and thesecond handle half 14(a)(ii) may be mirror images of each other. In somespecific embodiments, at least interior portions of the first handlehalf 14(a)(i) and the second handle half 14(a)(ii) (e.g., the internalcavity) may be mirror images of each other. In some embodiments, thecrossmember 52, the upright extension member 56, and the base 54 of thefirst handle half 14(a)(i) may be integrally formed from a unitary pieceof material, while the crossmember 52, the upright extension member 56,and the base 54 of the second handle half 14(a)(ii) may be integrallyformed from a unitary piece of material.

Forming the handle 14(a) in two halves, allows for easy attachment ofthe handle connection member 70(a) to the steering handle 14(a) by (i)placing the head 90 of the handle connection member 70(a) in the portionof the internal chamber defined by the first handle half 14(a)(i), (ii)aligning the second handle half 14(a)(ii) with the first handle half14(a)(i) so that the head is the portion of the internal chamber definedby the second handle half 14(a)(ii), and (iii) coupling the two handlehalves 14(a)(i) and 14(a)(ii) to one another (e.g., via the fasteners)while the head 90 is received in the internal cavity that iscooperatively formed by the first handle half 14(a)(i) and the secondhandle half 14(a)(ii).

Another embodiment of a steering control assembly 12(b) is illustratedin FIG. 16. Broadly, the steering control assembly 12(b) will include asteering handle 14(b) secured to a steering controller 44(a). Thesteering control assembly 12(b) may include many of the same componentsand may be configured to perform many of the same functions as thesteering control assembly 12(a) discussed above. As with steeringcontrol assembly 12(a), the steering control assembly 12(b) isconfigured such that steering handle 14(b) can be manually manipulatedforwardly and rearwardly and can be manually twisted in clockwise andcounterclockwise directions with respect to the steering controller44(b) to selectively depress buttons 46 to control the speed anddirection of rotation of the left and right traction elements 16 of theloader 10.

As shown in FIG. 17, the steering control assembly 12(b) comprises ahandle connection assembly 110 that is used to secure the steeringhandle 12(b) to the steering controller 44(b). The handle connectionassembly 110 may include a handle connection member 70(b) configured toextend upward into the internal cavity of the steering handle 14(b) in asimilar manner as the handle connection member 70(a). However, thehandle connection member 70(b) may be significantly longer than thehandle connection member 70(a), such that the handle connection member70(b) may extend into the internal cavity of the steering handle 14(b)up through base 54, through the upright extension member 56 and to (orinto) the crossmember 52. The handle connection member 70(b) may includea head 112 at its upper end and an annular base 114 at its lower end.

The handle connection assembly 110 may additionally include a pedestal120 to which the handle connection member 70(b) may be rigidly secured.In particular, the annular base 114 of the handle connection member70(b) may be secured to an upper surface of the pedestal 120 viafasteners. Notably, a bottom of the pedestal may be formed with a curvedbottom surface 122, which is formed similarly to the curved bottomsurface 57 of the base 54 of the steering handle 14(a) discussed above.Specifically, the curved bottom surface 122 ma include a substantiallyflat front section, a substantially flat rear section, a pair ofleft-side downwardly sloping sections, and a pair of right-sidedownwardly sloping sections. As such, the left-side downwardly slopingsections are formed on the sides of a left downward projection of thepedestal 120, and the right-side downwardly sloping sections are formedon the sides of a right downward projection of the pedestal 120. As aresult, the curved bottom surface 122 of the steering assembly 12(b) isformed on the handle connection assembly 110 that secures the steeringhandle 14(b) to the steering controller 44(b).

The handle connection assembly 110 may additionally include a tiltmember 124, which is configured to secure the handle connection member70(b) and the pedestal 120 to the steering controller 44(b). Inparticular as perhaps best illustrated by FIG. 18, The tilt member 124may be secured to the pedestal 120 via a threaded fastener 126 andassociated washer, which permit the pedestal 120 to rotate about a twistaxis 76 with respect to the tilt member 124. As shown, the twist axis 76will generally be aligned longitudinally with the threaded fastener 126,the tilt member 124, and the handle connection member 70(b). The tiltmember 124 will be secured to a second embodiment of a handle securementstructure 50(b) via a pivot pin 128. The pivot pin 128 will be held inplace within the tilt member 124 via a set screw 129 extending throughthe tilt member 124 and into engagement with the pivot pin 128. With thepivot pin 128 securing the tilt member 124 to the handle securementstructure 50(b), the pivot pin 128 will be aligned (and will present)the tilt axis 74. As illustrated in FIG. 17, the handle securementstructure 50(b) is secured to the steering controller 40(b), such thatthe handle connection assembly 110 and the steering handle 14(b) areoperably secured to the steering controller 44(b) (e.g., to depressassociated buttons 46 as required).

Returning to the pedestal 120, as perhaps best shown by FIG. 19, thepedestal includes an internal cavity with a pair of inwardly-orientated,triangular-shaped stops 130, which may form part of a twist stopassembly. When the pedestal 120 is secured to the tilt member 124, thestops 130 will be positioned at the same level as stop surfaces 132extending from the tilt member 124 (See stop surfaces 132 on FIG. 18).FIGS. 20(a) and 20(b) show a horizontal cross-sectional view cut throughthe pedestal 120 at the internal cavity that receives tilt member 124.The figures show that the pedestal 120 includes the stops 130 extendinginto the internal cavity at the same level as the stop surfaces 132 ofthe tilt member 124. These stops 130 are configured to restrict rotationof the steering handle 14(b) on the twist axis 76 within a certainrange. When the steering handle 14(b) is fully twisted in a clockwise orcounterclockwise manner, stop surfaces 132 of the tilt member 124contact the stops 130 and prevent further rotation of steering handle14(b) relative to the handle connection assembly 110 (including thehandle connection member 70(b)), the steering controller 44(b), andpanel support structure 22.

In some embodiments, the steering handle 14(b) is rotatable on the twistaxis 76 through a twist range of motion that is between 15 and 80degrees, or 25 and 60 degrees, or 30 and 50 degrees. In addition, thesteering handle 14(b) is shiftable on the tilt axis 74 through a tiltrange of motion that is between 15 and 80 degrees, or 25 and 60 degrees,or 30 and 50 degrees.

FIG. 21 further illustrates the steering handle 14(b) coupled togetherwith the handle connection assembly 110. FIG. 22 is a verticalcross-section showing how the components of the steering controlassembly 12(b) fit together. FIGS. 23(a)-27(b) show how the steeringhandle 14(b) can be manipulated with respect to the steering controller44(b) to control the loader 10.

FIGS. 23a (top view) and 23 b (side view) show the steering controlassembly 12(b) in a neutral position. When the steering control assembly12(b) is in the neutral position, none of the depressible buttons 46 aredepressed enough to cause rotation of the right or left tractionelements 16 of the loader 10. The steering control assembly 12(b) isbiased toward this neutral position so that if the operator of theloader 10 releases a hand grip on the steering handle 14(b), the loader10 stops. Specifically, the steering controller 44(b) can includes thevariable switch and a biasing mechanism for biasing the depressiblebuttons 46 upwardly, similar to that described for steering controller44(a) above. When the steering handle 14(a) is not being manuallymanipulated out of the neutral position, all the depressible buttons 46are fully extended and the steering handle 14(b) is maintained in theneutral position by the depressible buttons 46 pushing up against thesubstantially flat front and rear portions of the curved bottom surface122 of the pedestal 120. In some embodiments, the steering controller44(b) may be a hydraulic pilot control valve and movement of thedepressible buttons 46 directly adjusts the flow of hydraulic fluidthrough the control valve to control direction and speed of the rightand left traction elements 16 via the hydraulic motors.

FIGS. 23a and 23b show that the steering handle 14(b) is connected tothe steering controller 44(b) in a manner that allows the steeringhandle 14(b) to be shifted/tilted forward and rearward on tilt axis 74.Further, the steering handle 14(b) is connected to the steeringcontroller 44(b) in manner that allows the steering handle 14(b) to berotated/twisted clockwise and counterclockwise on twist axis 76. Thetilt axis 74 and twist axis 76 are maintained substantiallyperpendicular to one another, even during shifting or rotating of thesteering handle 14(b).

Certain of the remaining functionality of the steering control assembly12(b) is similar to that described above for steering control assembly12(a). As shown in FIGS. 24a (top view) and 24 b (side view) steeringhandle 14(b) can be tilted forward such that the right and left tractionelements 16 rotate forward at substantially the same speed, so theloader 10 travels straight forward. As shown in FIGS. 25a (top view) and25 b (side view), the steering handle 14(b) can be shifted rearwardcausing the right and left traction elements 16 rotate reward atsubstantially the same speed, so the loader 10 travels straight backward(i.e., in reverse). As shown in FIGS. 26a (top view) and 26 b (sideview), the steering handle 14(b) clockwise such that the right and lefttraction elements 16 rotate at substantially the same speed, with theleft traction element 16 rotating forward and the right traction element16 rotating rearward. In this configuration, the loader 10 turnsclockwise without traveling forward or backward. Finally, as shown inFIGS. 27a (top view) and 27 b (side view), the steering handle 14(b) canbe rotated counterclockwise such that the right and left tractionelements 16 rotate at substantially the same speed, with the righttraction element 16 rotating forward and the left traction element 16rotating rearward. In this configuration, the loader 10 turnscounterclockwise without traveling forward or backward.

When the steering handle 14(b) is simultaneously tilted (forward orrearward) and twisted (clockwise or counterclockwise), both the speed(fast or slow) and direction of travel (forward, backward, and turning)of the vehicle are easily and intuitively controlled by the operatorusing a single one hand on the steering handle 14(b).

As shown in FIG. 17, the steering handle 14(b) can be formed of twohalves—a first handle half 14(b)(i) and a second handle half 14(b)(ii).The first handle half 14(a)(i) may be secured to the second handle half14(a)(ii) via one or more forward/rearward extending fasteners or a snapfit-connection. Forming the handle 14(b) in two halves, allows for easyattachment of the handle connection assembly 110, including the handleconnection member 70(b) to the steering handle 14(b) by (i) placing thehandle connection member 70(b) in the internal chamber defined by thefirst handle half 14(b)(i), (ii) aligning the second handle half14(b)(ii) with the first handle half 14(b)(i) so that the handleconnection member 70(b) is the portion of the internal chamber definedby the second handle half 14(b)(ii), and (iii) coupling the two handlehalves 14(b)(i) and 14(b)(ii) to one another (e.g., via the fasteners)while the handle connection member 70(b) is received in the internalcavity that is cooperatively formed by the first handle half 14(b)(i)and the second handle half 14(b)(ii).

Although the steering handle assemblies 12(a), 12(b) described above areconfigured to pivot/rotate on two axes (i.e., a tilt axis 74 and thetwist axis 76), it should be understood that other embodiments of asteering handle assembly may be configured to include a steering handlethat can translate forward, rearward, and/or side-to-side relative to asteering controller, rather than pivot/rotate relative to the steeringcontroller. For example, in the embodiment depicted FIGS. 28a and 28b ,an embodiment of a steering handle assembly 12(c) is illustrated with asteering handle 14(c) mounted on a rail 150 that permits forward andrearward translation of the steering handle 14(c) relative to a steeringcontroller (identified by the depressible buttons 46). In such aconfiguration, forward and rearward movement of the loader 10 can becontrolled by sliding the steering handle 14(c) forward and rearward onthe rail 150, while turning of the loader 10 can be controlled bytilting the steering handle 14(c) left and right on an axis that iscoextensive with the rail 150.

Having thus described one or more embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:

What is claimed is:
 1. A vehicle steering assembly for controllingmovement of a vehicle having independently rotatable left and rightground-engaging traction elements, the vehicle comprising a controlpanel within reach of an operator of the vehicle, the control panelcomprising a panel support structure for supporting control or displaymechanisms of the vehicle, said steering assembly comprising: a steeringhandle coupled to the panel support structure and extending away fromthe panel support structure, wherein said steering handle comprises alaterally-extending crossmember and at least one upright extensionmember, wherein said crossmember and said upright extension member arerigidly connected to one another so that shifting of said crossmemberrelative to said extension member is substantially prevented, whereinsaid steering handle is shiftable in forward and rearward directions tothereby cause corresponding forward and rearward rotation of both ofsaid left and right traction elements, wherein said steering handle isrotatable in clockwise and counterclockwise directions to thereby causea change in the relative speeds and directions of rotation of said leftand right traction elements.
 2. The vehicle steering assembly of claim1, wherein the vehicle is a compact utility loader.
 3. The vehiclesteering assembly of claim 2, wherein the compact utility loadercomprises a loader system, a drive system, and a power source forpowering the loader system and the drive systems.
 4. The vehiclesteering assembly of claim 1, wherein said left and right tractionelements each comprises tracks.
 5. The vehicle steering assembly ofclaim 1, wherein a degree of forward or rearward shifting of saidsteering handle dictates a respective speed of forward or rearwardmovement of said vehicle, wherein a degree of twisting of said steeringhandle dictates a severity of turning of said vehicle.
 6. The vehiclesteering assembly of claim 1, wherein said steering handle includes onlya single upright extension member.
 7. The vehicle steering assembly ofclaim 1, wherein at least a portion of said crossmember and at least aportion of said upright extension member are integrally formed.
 8. Thevehicle steering assembly of claim 1, wherein said steering handle iscoupled to the panel support structure in a manner such that lateralshifting of said steering handle relative to the panel support structureis substantially prevented.
 9. The vehicle steering assembly of claim 1,wherein said steering handle is forward and rearward shiftable on a tiltaxis, wherein said steering handle is clockwise and counterclockwiserotatable on a twist axis, wherein said tilt axis and said twist axisare oriented substantially perpendicular to one another.
 10. The vehiclesteering assembly of claim 9, wherein said crossmember extendssubstantially perpendicular to said twist axis, wherein said twist axisextends through said crossmember.
 11. The vehicle steering assembly ofclaim 9, wherein said steering assembly comprises a twist stop assemblyfor restricting rotation of said steering handle relative to the panelsupport structure on the twist axis.
 12. The vehicle steering assemblyof claim 1, wherein said steering handle is biased toward a neutralposition so that said steering handle automatically returns to saidneutral position when not acted upon by the operator of the vehicle. 13.The vehicle steering assembly of claim 12, wherein said steeringassembly is configured such that (i) shifting said steering handleforward from said neutral position toward a forward position causesforward rotation of both said left and right traction elements, (ii)shifting said steering handle rearward from said neutral position towarda rearward position causes rearward rotation of both said left and righttraction elements, (iii) twisting of said steering handle clockwise fromsaid neutral position toward a clockwise twisted position causes forwardrotation of said left traction element and rearward rotation of saidright traction element, and (iv) twisting of said steering handlecounterclockwise from said neutral position toward a counterclockwisetwisted position causes forward rotation of said right traction elementand rearward rotation of said left traction element.
 14. The vehiclesteering assembly of claim 1, wherein said steering assembly furthercomprises a plurality of depressible buttons positioned generally belowsaid steering handle, wherein said buttons cooperatively control thespeed and direction of rotation of said left and right tractionelements, wherein said steering assembly comprises a plurality ofvariable switches, wherein each of said variable switches comprises atleast one of said depressible buttons, wherein speed of rotation of saidleft and right traction elements is determined by how far down saiddepressible buttons are depressed.
 15. The vehicle steering assembly ofclaim 14, wherein said steering handle comprises a base presenting alower surface having a curved topography, wherein said lower surface isconfigured to depress said buttons in response to manipulation of saidsteering handle by an operator of said vehicle.
 16. The vehicle steeringassembly of claim 1, wherein said steering assembly further comprises ahandle connection assembly for attaching said steering handle to saidpanel support structure, where said handle connection assembly comprisesa tilt hinge and a twist hinge, wherein said tilt hinge is configured topermit said steering handle to tilt forward and rearward relative tosaid panel support structure on a tilt axis, wherein said twist hinge isconfigured to permit said steering handle to twist clockwise andcounterclockwise relative to said panel support structure on a twistaxis.
 17. The vehicle steering assembly of claim 16, wherein said tiltaxis is substantially horizontal and said twist axis is substantiallyperpendicular to said tilt axis.
 18. A vehicle steering assembly forcontrolling movement of a vehicle having independently rotatable leftand right ground-engaging traction elements, the vehicle comprising acontrol panel within reach of an operator of the vehicle, the controlpanel comprising a panel support structure for supporting control ordisplay mechanisms of the vehicle, said steering assembly comprising: aplurality of depressible buttons coupled to the panel support structureand configured to cooperatively control the speed and direction ofrotation of said left and right traction elements; and a steering handlecoupled to said panel support structure and positioned generally oversaid depressible buttons, wherein said steering handle comprises alaterally-extending crossmember, an upright extension member, and abase, wherein said base presents a lower surface having a curvedtopography, wherein said lower surface is configured to depress saidbuttons in response to manipulation of said steering handle by saidoperator of said vehicle.
 19. The vehicle steering assembly of claim 18,wherein said steering handle is biased toward a neutral position so thatsaid steering handle automatically returns to said neutral position whennot acted upon by the operator of the vehicle, wherein (i) moving saidsteering handle forward out of said neutral position, without twistingsaid steering handle, depresses said front left and front right buttons,(ii) moving said steering handle rearward out of said neutral position,without twisting said steering handle, depresses said rear left and rearright buttons, (iii) twisting said steering handle clockwise from saidneutral position depresses said rear right and front left buttons, and(iv) twisting said steering handle counterclockwise from said neutralposition depresses said front right and rear left buttons.
 20. Thevehicle steering assembly of claim 19, wherein said depressible buttonsare upwardly biased, and wherein said steering handle is biased toward aneutral position by said depressible buttons so that said steeringhandle automatically returns to said neutral position when not actedupon by the operator of the vehicle.
 21. The vehicle steering assemblyof claim 20, wherein said lower surface includes a substantially flatfront section, a substantially flat rear section, a pair of right-sidedownwardly sloping sections, and a pair of left-side downwardly slopingsections.
 22. The vehicle steering assembly of claim 21, wherein (i)moving said steering handle forward out of said neutral position,without twisting said steering handle, causes said substantially flatfront portion to contact and depress said front left and front rightbuttons, (ii) moving said steering handle rearward out of said neutralposition, without twisting said steering handle, causes saidsubstantially flat rear portion to contact and depress said rear leftand rear right buttons, (iii) twisting said steering handle clockwisefrom said neutral position causes one of said right-side downwardlysloping sections to contact and depress said rear right button and oneof said left-side downwardly sloping sections to contact and depresssaid front left button, and (iv) twisting said steering handlecounterclockwise from said neutral position causes the other of saidright-side downwardly sloping sections to contact and depress said frontright button and the other of said left-side downwardly sloping sectionsto contact and depress said rear left button.
 23. A method forcontrolling movement of a vehicle having independently rotatable leftand right ground-engaging traction elements, said method comprising thesteps of: (a) providing a steering handle comprising alaterally-extending crossmember and an upright extension memberextending away from a control panel of the vehicle, wherein thecrossmember and the upright extension member are rigidly connected toone another so that shifting of the crossmember relative to theextension member is substantially prevented; (b) shifting the steeringhandle in a forward direction to cause forward rotation of both of theleft and right traction elements; (c) shifting the steering handle in arearward direction to cause rearward rotation of both of the left andright traction elements; and (d) rotating the steering handle in aclockwise or counterclockwise direction to cause to cause the left andright traction elements to rotate in opposing directions.
 24. The methodof claim 23, wherein the steering handle is configured to operablyengage with a plurality of depressible buttons that cooperativelycontrol a speed and a direction of rotation of the left and righttraction elements.
 25. The method of claim 24, wherein the steeringhandle is biased toward a neutral position so that after each of saidshifting of step (b), said shifting of step (c), and said rotating ofstep (d), the steering handle automatically returns to the neutralposition when not acted upon by the operator of the vehicle.
 26. Themethod of claim 25, wherein the depressible buttons are upwardly biased,and wherein the steering handle is biased toward a neutral position bythe depressible buttons so that the steering handle automaticallyreturns to the neutral position when not acted upon by the operator ofthe vehicle.
 27. The method of claim 25, wherein (i) moving the steeringhandle forward out of the neutral position, without twisting thesteering handle, depresses the front left and front right buttons, (ii)moving the steering handle rearward out of the neutral position, withouttwisting the steering handle, depresses s the rear left and rear rightbuttons, (iii) twisting the steering handle clockwise from the neutralposition depresses the rear right and front left buttons, and (iv)twisting the steering handle counterclockwise from the neutral positiondepresses the front right and rear left buttons.
 28. The method of claim24, wherein a bottom surface of the steering handle includes asubstantially flat front section, a substantially flat rear section, apair of right-side downwardly sloping sections, and a pair of left-sidedownwardly sloping sections, wherein (i) moving the steering handleforward out of the neutral position, without twisting the steeringhandle, causes the substantially flat front portion to contact anddepress the front left and front right buttons, (ii) moving the steeringhandle rearward out of the neutral position, without twisting thesteering handle, causes the substantially flat rear portion to contactand depress the rear left and rear right buttons, (iii) twisting thesteering handle clockwise from the neutral position causes one of saidright-side downwardly sloping sections to contact and depress the rearright button and one of the left-side downwardly sloping sections tocontact and depress the front left button, and (iv) twisting thesteering handle counterclockwise from the neutral position causes theother of the right-side downwardly sloping sections to contact anddepress the front right button and the other of the left-side downwardlysloping sections to contact and depress the rear left button.